Route inspection system

ABSTRACT

A system and method obtain first image data of a route at a location of interest from a first optical sensor disposed onboard a vehicle system moving along the route. The first image data depicts the route at the location of interest prior to passage of the vehicle system over the route at the location of interest. Second image data of the route at the location of interest is obtained from a second optical sensor disposed onboard the vehicle system. The second image data depicts the route at the location of interest after passage of the vehicle system over the route at the location of interest. A determination is made as to whether a change in the route has occurred at the location of interest by comparing the first image data with the second image data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 16/722,281, filed on 20 Dec. 2019, which is acontinuation-in-part of U.S. patent application Ser. No. 15/651,067,filed on 17 Jul. 2017, which claims priority to U.S. ProvisionalApplication No. 62/371,609, filed on 5 Aug. 2016, each of which ishereby incorporated by reference in its entirety.

This application is also a continuation-in-part of U.S. patentapplication Ser. No. 17/203,466, filed on 16 Mar. 2021, which claimspriority to U.S. Provisional Application No. 62/993,274, filed on 23Mar. 2020, each of which is hereby incorporated by reference in itsentirety.

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/532,522, filed on 22 Nov. 2021, which claims priority toU.S. Provisional Application No. 63/122,701, filed on 8 Dec. 2020, eachof which is hereby incorporated by reference in its entirety.

FIELD

Embodiments of the subject matter disclosed herein relate to systemsthat inspect routes for deviations in shape of the route or other damageto the route. Other embodiments relate to systems for vehicle controlbased on route inspection.

BACKGROUND

Vehicles traveling on routes depend on the routes having a defined orconsistent shape to ensure safe travel on the routes. As one example,rails of a track on which a rail vehicle moves need to have a definedshape that is free or substantially free (e.g., within manufacturing orinstallation tolerances) of deviations from the defined shape. Thermalmisalignments are one example of misaligned rails in a track that canpresent a hazard to an approaching rail vehicle. These misalignments caninclude sun kinks, as the misalignments develop along the route duringhot weather conditions when conductive components of the route (e.g., arail) expand. The expansion creates compressive tension in the metalcomponent, which causes the rail to buckle or otherwise becomemisaligned.

A thermal misalignment in a rail can include a lateral bending of therail that is outside of a straight shape or designated bend in the rail.FIGS. 1 through 4 illustrate examples of such thermal misalignments inrails of a track. A length of a thermal misalignment that poses problemsfor travel of a rail vehicle may be on the order of forty to sixty feet,or twelve to eighteen meters (e.g., along the length of the track). Sucha thermal misalignment can cause the rail to deviate from the intendedor previous location of the rail (e.g., the location or shape of therail as previously installed on a surface or as previously repaired) byas much as thirty inches or more (e.g., seventy-six centimeters).

Detection of these types of thermal misalignments in a route can aid inensuring safe travel of vehicles over the route.

BRIEF DESCRIPTION

In one embodiment, a method includes obtaining first image data of aroute at a location of interest from a first optical sensor disposedonboard a vehicle system moving along the route. The first image datadepicts the route at the location of interest prior to passage of thevehicle system over the route at the location of interest. The methodalso includes obtaining second image data of the route at the locationof interest from a second optical sensor disposed onboard the vehiclesystem. The second image data depicts the route at the location ofinterest after passage of the vehicle system over the route at thelocation of interest. The method also includes determining whether achange in the route has occurred at the location of interest bycomparing the first image data with the second image data.

In one embodiment, a system includes a controller configured to obtainfirst image data of a route at a location of interest from a firstoptical sensor disposed onboard a vehicle system moving along the route.The first image data depicts the route at the location of interest priorto passage of the vehicle system over the route at the location ofinterest. The controller also is configured to obtain second image dataof the route at the location of interest from a second optical sensordisposed onboard the vehicle system. The second image data depicts theroute at the location of interest after passage of the vehicle systemover the route at the location of interest. The controller is configuredto determine whether a change in the route has occurred at the locationof interest by comparing the first image data with the second imagedata.

In one embodiment, a system includes a controller configured to examineimage data of a common segment of a route obtained before and afterpassage of a vehicle system over the common segment of the route. Thecontroller is configured to determine one or more differences betweenthe image data and to determine that the common segment of the route isdamaged by passage of the vehicle system based on the one or moredifferences that are determined.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter described herein will be better understood fromreading the following description of non-limiting embodiments, withreference to the attached drawings, wherein below:

FIG. 1 illustrates one example of a thermal misalignment in a route;

FIG. 2 illustrates another example of a thermal misalignment in a route;

FIG. 3 illustrates another example of a thermal misalignment in a route;

FIG. 4 illustrates another example of a thermal misalignment in a route;

FIG. 5 illustrates one embodiment of a route inspection system disposedonboard a vehicle system;

FIG. 6 illustrates one embodiment of the route inspection system shownin FIG. 5;

FIG. 7 illustrates a flowchart of one embodiment of a method forinspecting a route;

FIG. 8 illustrates one example of sensor data obtained by the routeinspection system;

FIG. 9 illustrates another example of sensor data obtained by the routeinspection system;

FIG. 10 schematically illustrates calculation of an instantaneous degreeof curvature (DoC) of a route according to one example;

FIG. 11 schematically illustrates a top view of a vehicle shown in FIG.5 during travel on a route;

FIG. 12 schematically illustrates another top view of the vehicleaccording to the example shown in FIG. 11;

FIG. 13 illustrates a relationship between a separation distance betweena sensor of the route inspection system and a reference line and atheta_(x) distance according to one example;

FIG. 14 also illustrates the relationship between the separationdistance and the theta_(x) distance;

FIG. 15 illustrates another example of the vehicle system shown in FIG.5 traveling on the route also shown in FIG. 5 prior to moving over alocation of interest in the route;

FIG. 16 illustrates the vehicle system shown traveling on the routeafter moving over the location of interest in the route;

FIG. 17 illustrates one example of image data output by a leading sensorshown in FIG. 5;

FIG. 18 illustrates one example of image data output by a trailingsensor shown in FIG. 5;

FIG. 19 illustrates one example of a mirror translation of the imagedata output by the trailing sensor;

FIG. 20 illustrates another example of image data that may be output bythe trailing sensor after the vehicle system has traveled over thesegment of the route depicted in the image data output by the leadingsensor shown in FIG. 17;

FIG. 21 illustrates a mirror translation of the image data shown in FIG.20;

FIG. 22 illustrates an overlay of the mirror translation of the imagedata shown in FIG. 21 onto the image data shown in FIG. 17; and

FIG. 23 illustrates a flowchart of one example of a method forinspecting a route.

DETAILED DESCRIPTION

One or more embodiments of the inventive subject matter described hereindetect misalignments in a route being traveled by a vehicle. Themisalignments may be thermal misalignments detected from a systemonboard a moving vehicle. This allows the misalignments to be detectedand one or more responsive actions initiated or implemented before themisalignments can present hazards to one or more vehicles subsequentlytraveling over the same segment of the route. One or more embodiments ofthe systems described herein can be disposed onboard vehicle systemsformed from two or more vehicles traveling together along a route. Thesystems may be onboard the last trailing vehicle (e.g., along adirection of travel) for monitoring segments of the route that wererecently traversed by the vehicle system. Additionally or alternatively,the systems may be onboard the first leading vehicle (e.g., along thedirection of travel) for monitoring upcoming segments of the route yetto be traversed by the vehicle system (to allow responsive actions to beimplemented or triggered prior to worsening the misalignment for one ormore subsequent vehicle systems).

The systems described herein may monitor curvatures of a route, such asa track formed from one or more rails. While the description hereinfocuses on rail vehicles (e.g., locomotives, rail cars, etc.) and railvehicle systems (e.g., trains, consists, etc.), not all embodiments arelimited to rail vehicles or rail vehicle systems. One or moreembodiments may be used with other vehicles or vehicle systems travelingon routes that may become misaligned, such as automobiles or miningvehicles traveling along routes that may be partially washed out orotherwise damaged, high rail vehicles, etc.

The systems can utilize sensors mounted on the moving vehicles tomeasure degrees of curvature (DoCs) of the route being traveled upon. Inone embodiment, the DoC is a measurement of a change in trajectory ofthe route after transiting a section of a curve with a designated length(e.g., a chord length of 100 feet or 30.5 meters, or another distance).Optionally, an approximation of the DoC, or a scaled valued (using adifferent chord length) of the DoC may be measured and used.

The measured values of the DoC are used to calculate a nominal DoC of asegment of the route that was just transited by the vehicle system(referred to herein as a traveled segment), or a segment of the routeabout to be transited by the vehicle system (referred to herein as anupcoming segment). The nominal DoC can represent an average, movingaverage, zero frequency, or filtered (e.g., low pass filtered) curvatureof the route. The nominal DoC can be calculated as the average or movingaverage of the DoCs measured (with the moving average being an averageof a designated number of most recently obtained DoC measurements, suchas the most recent ten measurements). Alternatively, the nominal DoC maybe determined in another manner.

The nominal DoC may change at different locations along the route and/orat different times during movement of the vehicle over the route due tochanges in curvature in the route (e.g., changes in radii of curvaturein the route). The rate at which the nominal DoC changes (e.g., withrespect to distance along the route) may be restricted. For example,legal or regulatory restrictions may limit how sharply different routescan curve in different locations, for different speed limits, etc. Thesystems described herein may prevent the nominal DoC from changing at arate that is faster than a designated rate (e.g., which may be operatorselected or obtained from laws or regulations). This can allow forchanges in the DoC that are caused by misalignments in the route tostand out or apart from changes in the nominal DoC that are not causedby misalignments of the route.

To detect a misalignment such as a thermal misalignment, a deviation inthe DoC from the nominal DoC can be calculated by subtracting thenominal DoC from an instantaneous DoC measurement. The instantaneous DoCmeasurement can be a single measurement of the DoC, but does notnecessarily require being instantly measured with respect to time. Thedeviation between the instantaneous DoC and the nominal DoC can bereferred to as a DoC deviation or difference. A DoC deviation thatexceeds a threshold can indicate a misalignment in the route, such as athermal misalignment. In order to detect relatively very smallmisalignments, the DoC deviations associated with a short length of theroute (e.g. fifty feet or fifteen meters or less) may be summed togetherto form an accumulated DoC deviation. The accumulated DoC deviation thatexceeds a designated threshold is indicative of a misalignment.

One or more technical effects of the inventive subject matter describedherein is the detection of misalignments in a route during movement of avehicle along the route, and the implementation of responsive actions inresponse thereto in order to ensure the safe travel of the vehicleand/or other vehicles. For example, responsive to detecting a thermalmisalignment in the route, the systems described herein may direct thevehicle to automatically slow or stop movement, communicate a signal toother vehicles heading toward and/or scheduled to travel over thethermal misalignment to warn the other vehicles, communicate a signal toother vehicles heading toward and/or scheduled to travel over thethermal misalignment to automatically and remotely control the othervehicles to slow or stop movement during travel over the thermalmisalignment, communicate a signal to other vehicles heading towardand/or scheduled to travel over the thermal misalignment toautomatically and remotely control the other vehicles to change routesto avoid traveling over the thermal misalignment, communicate a signalto one or more route devices (e.g., switches, gates, etc.) that controlwhere vehicles travel on the route that automatically and remotelycontrols the route device(s) to cause the other vehicles to travel onother routes (e.g., change a state of a switch to cause other vehiclesto travel around and not over the thermal misalignment), communicate asignal to a scheduling or dispatch facility to cause the schedule of oneor more other vehicles to be changed to cause the one or more othervehicles to not travel over the thermal misalignment, and/or communicatea signal to repair personnel that causes the personnel to travel to thethermal misalignment and inspect and/or repair the misalignment. Theseresponsive actions can prevent damage to route infrastructure, preventlosses of cargo carried by the vehicles, and/or prevent a reduction ofcargo or vehicular throughput along the route that could result from aderailment of the vehicles caused by the misalignment.

FIG. 5 illustrates one embodiment of a route inspection system 500disposed onboard a vehicle system 502. The route inspection systemincludes sensors 504, 506 disposed onboard one or more vehicles 508, 510of the vehicle system and a monitoring system 512 (also referred toherein as a monitor) that examines data provided by the sensors toidentify misalignments in a route 514 being traveled by the vehiclesystem. The vehicles 508 represent propulsion-generating vehicles, suchas locomotives, automobiles, mining vehicles, or the like. The vehicles510 represent non-propulsion-generating vehicles, such as rail cars,trailers, or the like. The vehicles 508, 510 in the vehicle systemtravel together along one or more routes. The vehicles 508, 510 may bemechanically coupled with each other. Optionally, the vehicles 508 maybe logically coupled with each other without being mechanically coupledwith each other. For example, the vehicles 508 may communicate with eachother to coordinate movements of the vehicles 508 so that the vehicles508, 510 travel together along the route, such as in a platoon. Whilethe vehicle system and vehicles are shown and described herein as railvehicle systems and rail vehicles, not all embodiments are limited torail vehicles or rail vehicle systems. While the route may be describedas a track formed from one or more rails, not all embodiments arelimited to tracks or rails. For example, embodiments of the subjectmatter described herein may be used to detect warping, washouts, orother problems or damage to automobile routes (e.g., roads). The numberand arrangement of the vehicles in the vehicle system are provided asone non-limiting example. Alternatively, the vehicle system may beformed from a different number of vehicles 508 and/or vehicles 510. Inone embodiment, the vehicle system may be formed from a single vehicle508 or 510.

The sensors may generate data representative of curvatures of the routeduring movement of the vehicle system along the route. The sensor 504may be referred to as a leading sensor as the sensor 504 obtains dataindicative of curvatures in segments of the route that are ahead of thevehicle system along a direction of travel or movement 516 of thevehicle system. The sensor 506 may be referred to as a trailing sensoras the sensor 506 obtains data indicative of curvatures in segments ofthe route that are behind the vehicle system (e.g., that the vehiclesystem recently traveled over) along the direction of travel or movementof the vehicle system. The route inspection systems described herein maydetermine DoCs of upcoming segments of routes being traveled upon and/orof segments of routes that the vehicle systems recently traveled over(e.g., behind the vehicle systems).

FIG. 6 illustrates one embodiment of the route inspection system 500shown in FIG. 5. The route inspection system is shown as being disposedonboard a single vehicle 508 in FIG. 6, but optionally may be disposedonboard two or more vehicles. The route inspection system includes asensor 600, which can represent the leading sensor 504 or the trailingsensor 506 shown in FIG. 5. The sensor 600 can be an optical sensor thatobtains or measures information using light and generates dataindicative of the information. As one example, the optical sensor can bea two or three-dimensional camera. Alternatively, the optical sensor canbe a lidar sensor, a structured light sensor, infrared sensor, photomultiplied sensor (e.g., night vision sensor), white light sensor, radarsensor, spectrographic light sensor, etc.

The sensor is shown as being connected to an external surface of a truckor bogie of the vehicle, but optionally may be disposed elsewhere. Forexample, the sensor may be connected on a top, front, or rear surface ofthe vehicle and oriented toward the route such that the field of view ofthe sensor encompasses at least part of the route under examination.Optionally, the optical sensor may be disposed inside the vehicle, suchas inside an operator cab of the vehicle, with the field of view of thesensor including at least a portion of the route under examination(e.g., via or through one or more windows or openings of the vehicle).

The monitoring system 512 receives data provided by the sensor anddetermines DoC in the route, nominal DoCs of the route, and DoCdeviations based on or using this data. The monitoring system representshardware circuitry that includes and/or is connected with one or moreprocessors, such as one or more microprocessors, field programmable gatearrays, and/or integrated circuits. The arithmetic/logic unit (ALU) ofone or more processors of the monitoring system can perform thecalculations and comparisons described herein, and can change a state ofone or more registers or flip flops to cause a buffer, such as a two- orthree-state buffer, to drive outputs onto a wire indicative of thecalculations or comparisons.

A controller 602 of the vehicle represents hardware circuitry thatincludes and/or is connected with one or more processors, such as one ormore microprocessors, field programmable gate arrays, and/or integratedcircuits. The controller controls operation of the vehicle, andgenerates signals communicated to a propulsion system 604 and/or brakingsystem 606 of the vehicle to control movement of the vehicle. Thepropulsion system represents one or more engines, alternators,generators, batteries, motors, or the like, that operate to propel thevehicle along the route. The braking system represents one or morebrakes, such as air brakes, friction brakes, or the like. The controllercan communicate with the monitoring system and/or an input device 608 toreceive instructions on how to control movement of the vehicle. Theinput device can represent one or more throttles, steering wheels,pedals, buttons, levers, touchscreens, keyboards, etc., that can beactuated by an operator to instruct the controller how to controlmovement of the vehicle. The controller can generate signalscommunicated to the propulsion system and/or braking system to implementthe instructions received via the input device and/or monitoring system.The monitoring system can generate and communicate signals (e.g., theALU of one or more processors of the monitoring system can change astate of one or more registers or flip flops to cause a buffer, such asa two- or three-state buffer, to drive outputs onto a wire indicative ofthe signals) to the controller responsive to detecting a misalignment inthe route. These signals may cause the controller to automatically slowor stop movement of the vehicle.

An output device 610 represents one or more display devices,touchscreens (which may be different from or the same as the inputdevice), speakers, lights, transceiving circuitry (e.g., modems,antennas, etc.), web enabled interfaces, web clients/servers, cloudinterfaces, or the like, that visually and/or audibly notify an operatorof the vehicle of misalignments in the route and/or communicate with oneor more locations off-board the vehicle of the misalignment. Themonitoring system can generate and communicate signals (e.g., the ALU ofone or more processors of the monitoring system can change a state ofone or more registers or flip flops to cause a buffer, such as a two- orthree-state buffer, to drive outputs onto a wire indicative of thesignals) to the output device responsive to detecting a misalignment inthe route. These signals may cause the output device to notify theoperator of the vehicle and/or one or more off-board locations of themisalignment.

A memory 612 represents one or more tangible and non-transitory computerreadable media, such as computer hard drives, optical disks, read onlymemories, random access memories, or the like. The monitoring system cangenerate and communicate signals (e.g., the ALU of one or moreprocessors of the monitoring system can change a state of one or moreregisters or flip flops to cause a buffer, such as a two- or three-statebuffer, to drive outputs to an address bus for writing information tothe memory) to the memory to store instantaneous DoCs, nominal DoCs,and/or DoC deviations calculated by the ALU of the monitoring system.The monitoring system can obtain the nominal DoCs and/or instantaneousDoCs used to calculate the nominal DoCs and/or DoC deviations from thememory (e.g., the ALU can obtain inputs received from one or morebuffers driven by signals on a wire connected with the buffers and thememory).

FIG. 7 illustrates a flowchart of one embodiment of a method 700 forinspecting a route. The method 700 may be performed by the routeinspection system described herein. The data used to inspect the routecan be sensed and provided to the one or more processors of themonitoring system by the sensor or sensors. The ALU of one or moreprocessors of the monitoring system may perform the comparisons and thecalculations described herein using this data. The memory can be writtento and accessed by the ALU of one or more processors of the monitoringsystem as needed for these calculations and comparisons. The method 700may represent software directing the operations of the monitoringsystem, or may represent an algorithm that is used to create suchsoftware.

At 702, sensor data of the route being traveled by the vehicle system isobtained. This sensor data can include static images, videos, frames ofa video, or other optical information representative of a segment of theroute recently traveled over by the vehicle system and/or an upcomingsegment of the route. The sensor data may be received by the monitoringsystem from the sensor(s). At 704, a reference location or point in thesensor data is determined. This reference location may be referred to asa datum or a feature of interest in the route, and represents a locationon the route and/or a fixed distance from the route.

FIG. 8 illustrates one example of sensor data 800 obtained by themonitoring system from one or more of the sensors. The sensor data is animage or frame of a video, and shows a segment of the route. A referenceline 802 indicates a designated or fixed distance away from the sensorthat provided the sensor data 800 toward the route. This distance may bethree meters, six meters, or another distance. In one embodiment, themonitoring system can examine pixels of the sensor data along thereference line to identify where the reference location is located inthe sensor data. For example, the ALU of one or more processors in themonitoring system can compare intensities and/or chromaticities of thepixels along the reference line in order to identify locations of routefeatures of interest 804, 806 (such as rails, painted lines on a road,etc.) of the route. The pixels representative of the rails may haveintensities and/or chromaticities that are within a designated range ofeach other (e.g., values within 5%, 10%, or 20% of each other), whilepixels representative of other objects in the sensor data may haveintensities and/or chromaticities that are outside of this range. Bycomparing the intensities and/or chromaticities, the ALU of one or moreprocessors in the monitoring system can determine which pixels areindicative of the features of interest in the route. Optionally, aspectsof the sensor data other than pixels may be examined. For example,sensors such as infrared sensors, photo multiplied sensors (e.g., nightvision sensors), white light sensors, lidar sensors, radar sensors,spectrographic light sensors, etc., may have other aspects or featuresother than pixels that are examined. These other sensors may outputsensor data such as volts or amps (from an analog-to-digital converter),DB or DBmv radio output, light intensities (e.g., in lumens per foot orlux per foot), etc.

The monitoring system may select a reference location 808 in the sensordata along the reference line during travel on a straight section of theroute. As described below, locations in subsequently acquired sensordata are compared to this reference location to determine the DoC ofsegments of the route. The reference location may be calculated by oneor more ALUs of the monitoring system as an intersection of a locationin the route with the reference line 802. In one embodiment, thereference location is the midway point between the features of interest,such as the center of the route (as shown in FIG. 8), along thereference line. Alternatively, the reference location may be anintersection between an inner or outer edge of the features of interestand the reference line.

Returning to the description of the method 700 shown in FIG. 7, at 706,one or more locations of interest in subsequent sensor data aredetermined. The monitoring system may examine multiple images or videoframes of the sensor data representative of later times and/or differentlocations along the route to identify locations of interest. Thelocations of interest that are identified may be the same relativelocation on the route, but may be located elsewhere in the subsequentsensor data (different than the sensor data used to identify where thereference location is located) due to curvature of the route. Themonitoring system can compare the locations of interest with thereference location to determine differences between these locations.These differences can be indicative of curvature of the route.

FIG. 9 illustrates another example of sensor data 900 obtained by themonitoring system from one or more of the sensors. The sensor data 900may be an image or video frame representative of the route at a time orlocation subsequent to the sensor data 800 shown in FIG. 8. Themonitoring system examines the sensor data 900 in a similar manner to asdescribed above in connection with the sensor data 800 shown in FIG. 8to identify a location of interest 908 in the sensor data 900. Forexample, the monitoring system can examine the sensor data 900 to findthe midpoint between the rails 804, 806 of the route 514 as the locationof interest 908.

As shown in FIGS. 8 and 9, the location of interest 908 in the sensordata has moved (e.g., to the left in the perspective of FIGS. 8 and 9)away from the location of the reference location 808 in the sensor data.This movement or change in the reference location indicates that theroute is curving. The DoC of the route (e.g., the instantaneous DoC ofthe route) can be determined based on this change in the referencelocation.

Returning to the description of the method 700 shown in FIG. 7, at 708,an instantaneous DoC in the route is determined based on the differencebetween the location of interest and the reference location. FIG. 10schematically illustrates calculation of an instantaneous DoC of a routeaccording to one example. The DoC represents a difference in trajectory(or heading or path of the route) after traveling along an arc of achord length C. The chord length can be selected by an operator of themonitoring system or may have a default value, such as 100 feet or 30.5meters, or another distance. The larger that this difference is betweenthe trajectories, the sharper the curve is in the route. The smallerthis difference is, the more gradual the curve is in the route.

For example, a DoC can be expressed as or can represent an angulardifference D between a previous trajectory 1000 and a subsequenttrajectory 1002. A radius of curvature R of the segment of the route canbe calculated based on the difference D in trajectories as follows:

$R = \frac{C}{2\sin\frac{D}{2}}$

As the difference in trajectories D becomes larger (e.g., closer toninety or 270 degrees), the radius of curvature R becomes smaller. But,the monitoring system may not be able to calculate the DoC directly fromthe sensor data. Instead, the monitoring system may use differences orchanges in the reference location in the sensor data to approximate orestimate the DoC of the route.

FIG. 11 schematically illustrates a top view of the vehicle 508 duringtravel on the route 514 and the sensor data 900 shown in FIG. 9. Alsoshown in FIG. 11, the location of interest 908 along the route 514 hasmoved away from the reference location 808, which indicates that theroute is curving. One or more ALUs of the processors in the monitoringsystem can compare the locations of the location of interest and thereference location in the sensor data to determine how far the locationof interest is from the reference location. A theta angle Θ representsthe angular difference or angle between a straight reference line 1100extending to the reference location 808 and a straight examination line1102 to the location of interest 908.

FIG. 12 schematically illustrates another top view of the vehicle 508according to the example shown in FIG. 11. The monitoring system (e.g.,the ALU of one or more processors of the monitoring system) cancalculate a distance between the location of interest 908 in the sensordata 900 and the reference location 808 in the sensor data 800 todetermine a DoC of the route. This distance is referred to as atheta_(x) distance, as shown in FIG. 12. This theta_(x) distance and aseparation distance (d+d′) from the sensor 600 to the fixed distancefrom the sensor 600 (e.g., the reference line 802) form a right angle,which forms a right triangle, as shown in FIG. 12. The theta_(x)distance may be measured in units of pixels or other units within thesensor data by the monitoring system (e.g., the ALU of one or moreprocessors of the monitoring system). The monitoring system (e.g., theALU of one or more processors of the monitoring system) may then convertthis pixel distance by multiplying this pixel distance (or number ofpixels) by a scaling factor that converts the pixel distance to anotherdistance (e.g., inches, centimeters, etc.).

In one embodiment, the separation distance (d+d′) is a combination(e.g., sum) of a distance (d′) from halfway between the front and reartrucks of the vehicle (e.g., trucks of a locomotive) to an outer end1200 of the vehicle and a distance (d) from an outer end 1200 of thevehicle to the location of the reference line. Because the sensor doesnot move with respect to the vehicle and the reference line represents afixed location relative to the sensor and/or outer end of the vehicle,the separation distance is a fixed distance in one embodiment.

FIGS. 13 and 14 illustrate relationships between the separation distance(between the sensor 600 and the reference line 802) and the theta_(x)distance according to one example. Theta (θ) is the angle measured bythe sensor using a chord length of theta_(hyp). Theta_(hyp) and θ can beused to calculate D for a chord length C. The value of theta_(hyp)varies based on the value of θ:

${theta_{hyp}} = \frac{theta_{x}}{\sin\;\theta}$

The radius of curvature R of the route can be determined as follows:

$R = \frac{chordlength}{2\mspace{11mu}{\sin({angle})}}$

This radius can be determined from the values of the chord length (C)and the value of D:

$R = \frac{C}{2\mspace{11mu}\sin\frac{D}{2}}$

The chord length C can have a fixed value (e.g., 100 feet) in oneembodiment.

Optionally, the radius of curvature R can be calculated from theta_(hyp)and θ:

$R = \frac{theta_{hyp}}{2\;\sin\mspace{11mu}\theta}$

where theta_(hyp) is a variable chord length.

This relationship can be used to convert θ and theta_(hyp) into the DoC(e.g., D) by setting the equations equal to each other:

$\frac{C}{2\sin\frac{D}{2}} = \frac{theta_{hyp}}{2\mspace{11mu}\sin\;\theta}$

The value of the DoC (e.g., D in FIG. 14) can be determined as follows:

$D = {2\sin^{- 1}\frac{C\sin^{2}\theta}{theta_{x}}}$

If the value of the chord length C is known to the monitoring system(e.g., a default value is used, such as 100 feet or 1200 inches, and isaccessible by the ALU in the memory via the address bus), then theinstantaneous DoC can be calculated as:

$D = {2\sin^{- 1}\frac{1200\mspace{11mu}\sin^{2}\theta}{theta_{x}}}$

Returning to the description of the method 700 shown in FIG. 7, themethod 700 can include two sets of operations performed concurrently,simultaneously, or sequentially. A first set of operations (e.g., 710through 718) is performed to determine and update the nominal DoC of theroute being traveled upon and a second set of operations (e.g., 720through 726) is performed to compare the instantaneous DoC with thenominal DoC to determine whether a misalignment in the route isdetected.

At 710, the nominal DoC of the route is determined. The nominal DoC maybe calculated by the monitoring system (e.g., the ALU of one or moreprocessors) obtaining previous measurements of the instantaneous DoC(e.g., from the memory) and calculating a moving average in oneembodiment. For example, the monitoring system may calculate an averageof the ten, twenty, fifty, or the like, most recently calculatedinstantaneous DoCs as the nominal DoC. Optionally, the monitoring systemmay use another calculation, such as an average of the instantaneousDoCs determined during travel on a curved portion of the route.

At 712, a rate in change in the nominal DoC is determined. The nominalDoC may change as the vehicle moves along the route due to the curvaturein the route not being the same along the entirety of the route. Severalnominal DoCs may be determined (e.g., at 710) and stored in the memory.The monitoring system (e.g., the ALU of one or more processors) mayaccess the memory and examine how quickly the nominal DoCs are changingwith respect to distance along the route.

At 714, a determination is made as to whether the nominal DoC ischanging at a rate that exceeds a designated rate of change. Thecurvature in a route may be limited by legal and/or regulatoryrestrictions to prohibit the route from curving too sharply (and therebyintroducing a significant safety risk). As one example, 37 C.F.R. § 213may set forth restrictions on the geometric of a rail track, which caninclude limitations on the curvature of the track.

The monitoring system (e.g., the ALU of one or more processors) maycompare the rate of change in the nominal DoC (e.g., determined at 712)with a designated rate of change stored in the memory (e.g., which theALUs may access via the address bus of the processor(s) of themonitoring system). The designated rate of change may be dictated by oneor more laws or regulations, or may be input by an operator (e.g., viathe input device).

If the rate of change in the nominal DoC exceeds the designated rate ofchange, then the nominal DoC is changing too rapidly (e.g., relative todistance along the route) and may need to be limited to providemeaningful analysis. For example, the rapid rate of change in thenominal DoC may be indicative of a thermal misalignment occurring over arelatively long portion of the route instead of a sharp curve in theroute. To avoid the rapid rate of change in the nominal DoC from beingincorrectly identified as the curvature in the route without anymisalignment, flow of the method 700 may proceed toward 716 in order tolimit the nominal DoC change.

But, if the rate of change in the nominal DoC does not exceed thedesignated rate of change, then the nominal DoC is not changing toorapidly and may be used for detection of misalignments in the route. Asa result, flow of the method 700 may proceed toward 718.

At 716, the value of the nominal DoC is restricted (e.g., changed orprevented from changing) so that the rate of change in the nominal DoCdoes not exceed the designated rate of change. For example, if a currentvalue of the nominal DoC (e.g., determined at 710) would cause the rateof change in the DoC to exceed the designated rate of change, then themonitoring system (e.g., the ALU of one or more processors) may reducethe rate of change by changing the value of the nominal DoC. Themonitoring system may iteratively reduce the nominal DoC by increasinglylarger values until the monitoring system calculates that the rate ofchange in the nominal DoC (with the reduced value) no longer exceeds thedesignated rate of change. The monitoring system may then use thisreduced value of the nominal DoC, as described below. The ALU of one ormore processors may write this reduced value to the memory (e.g., viathe address bus of the one or more processors).

At 718, the value of the nominal DoC is set. If the monitoring systemdid not need to adjust the value of the nominal DoC at 714 and 716, thenthe value of the nominal DoC may be set (e.g., stored in the memory viathe address bus of one or more processors of the monitoring system) asthe value calculated at 710. But, if the monitoring system did adjustthe value of the nominal DoC at 714 and 716 (e.g., to prevent the rateof change in the nominal DoC from being too large), then the value ofthe nominal DoC may be set (e.g., stored in the memory via the addressbus of one or more processors of the monitoring system) as the valuedetermined at 716.

Flow of this portion of the method 700 may then return toward 706. Forexample, after setting the value of the nominal DoC, anotherinstantaneous DoC may be determined, the nominal DoC updated using thisadditional instantaneous DoC, and the rate of change in the nominal DoCexamined to determine whether to restrict the value of the DoC, asdescribed above. This process may be repeated several times to keepupdating the nominal DoC.

With respect to the set of operations in the method 700 at 720 through726, at 720, a deviation from the nominal DoC is determined. Forexample, the instantaneous DoC determined at 708 may be compared withthe nominal DoC to determine a difference between the instantaneous DoCand the nominal DoC. The monitoring system (e.g., the ALU of one or moreprocessors in the monitoring system) may calculate this difference bysubtracting the nominal DoC from the instantaneous DoC (or bysubtracting the instantaneous DoC from the nominal DoC). The differencemay represent the DoC deviation that is determined at 720.

At 722, a determination is made as to whether the DoC deviation exceedsa designated threshold. The monitoring system (e.g., the ALU of one ormore processors in the monitoring system) can compare the DoC deviationto a designated threshold that may be stored in the memory. Thedesignated threshold may have a non-zero value to prevent smalldeviations from incorrectly being identified as misalignments in theroute. The designated threshold may have a value that is set by anoperator (e.g., via the input device). If the DoC deviation exceeds thethreshold, then the deviation may indicate a misalignment in the route.As a result, flow of the method 700 can proceed toward 724.Alternatively, if the DoC deviation does not exceed the threshold, thenthe deviation may not indicate a misalignment in the route. As a result,flow of the method 700 can return toward 706 to repeat the determinationand examination of another instantaneous DoC.

In another embodiment, the monitoring system may compare several DoCdeviations to the designated threshold. The monitoring system (e.g., theALU of one or more processors) may sum a designated number of DoCdeviations (e.g., the most recent ten, twenty, etc., of the DoCdeviations) to calculate a summed DoC deviation. If the summed DoCdeviation exceeds the threshold, then the deviations may indicate amisalignment in the route. As a result, flow of the method 700 canproceed toward 724. Alternatively, if the summed DoC deviation does notexceed the threshold, then the summed deviation may not indicate amisalignment in the route. As a result, flow of the method 700 canreturn toward 706 to repeat the determination and examination of anotherinstantaneous DoC.

As another example, the monitoring system (e.g., the ALU of one or moreprocessors) may calculate an average (or moving average) of a designatednumber of DoC deviations (e.g., the most recent ten, twenty, etc., ofthe DoC deviations) to calculate an averaged DoC deviation. If theaveraged DoC deviation exceeds the threshold, then the deviations mayindicate a misalignment in the route. As a result, flow of the method700 can proceed toward 724. Alternatively, if the averaged DoC deviationdoes not exceed the threshold, then the averaged deviation may notindicate a misalignment in the route. As a result, flow of the method700 can return toward 706 to repeat the determination and examination ofanother instantaneous DoC.

At 724, the segment of the route is identified as having a misalignment.For example, the portion of the route from which the instantaneous DoCor several instantaneous DoCs that were measured and that resulted inthe monitoring system identifying the DoC deviation, summed DoCdeviation, and/or averaged DoC deviation as being indicative of amisalignment may be identified as having a misalignment. The monitoringsystem (e.g., the ALU of one or more processors) may store data or adatum in the memory that represents the misalignment and/or a locationof the misalignment along the route. The location of the misalignmentalong the route may be provided by the input device, which optionallycan include a global positioning system, dead reckoning system, or otherlocation determining system (e.g., a tachometer that measures speed ofthe vehicle and a clock that measures passage of time to allow thelocation of the vehicle along the route to be calculated).

At 726, one or more responsive actions are implemented. One or more ofthese actions may be performed in response to identifying themisalignment. For example, the monitoring system (e.g., the ALU of oneor more processors) may generate and communicate a signal to thecontroller to direct the vehicle to automatically slow or stop movement.Optionally, the monitoring system may generate and communicate a signalto the output device to direct the output device to communicate a signalto other vehicles heading toward and/or scheduled to travel over thethermal misalignment to warn the other vehicles. Additionally oralternatively, the monitoring system may generate and communicate asignal to the output device to direct the output device to communicate asignal to other vehicles heading toward and/or scheduled to travel overthe thermal misalignment to automatically and remotely control the othervehicles to slow or stop movement during travel over the thermalmisalignment.

As another example, the monitoring system may generate and communicate asignal to the output device to direct the output device to communicate asignal to other vehicles heading toward and/or scheduled to travel overthe thermal misalignment to automatically and remotely control the othervehicles to change routes to avoid traveling over the thermalmisalignment. Optionally, the monitoring system may generate andcommunicate a signal to the output device to direct the output device tocommunicate a signal to one or more route devices (e.g., switches,gates, etc.) that control where vehicles travel on the route thatautomatically and remotely controls the route device(s) to cause theother vehicles to travel on other routes (e.g., change a state of aswitch to cause other vehicles to travel around and not over the thermalmisalignment).

The monitoring system may generate and communicate a signal to theoutput device to direct the output device to communicate a signal to ascheduling or dispatch facility to cause the schedule of one or moreother vehicles to be changed to cause the one or more other vehicles tonot travel over the thermal misalignment. Optionally, the monitoringsystem may generate and communicate a signal to the output device todirect the output device to communicate a signal to repair personnelthat causes the personnel to travel to the thermal misalignment andinspect and/or repair the misalignment.

In one embodiment, a system (e.g., a route inspection system) includesone or more processors configured to identify a reference location insensor data provided by one or more sensors onboard a vehicle system.The reference location is identified along a route being traveled by thevehicle system. The one or more processors also are configured toidentify a location of interest in subsequent sensor data provided bythe one or more sensors. The location of interest identified along theroute being traveled by the vehicle system. The one or more processorsalso are configured to determine a degree of curvature in the routebased on a difference between the reference location and the location ofinterest.

In one example, the one or more sensors include one or more of a cameraor a lidar sensor.

In one example, the sensor data and the subsequent sensor data includeone or more of images, a video, or video frames of the route.

In one example, the one or more sensors include an optical sensororiented toward the route along a direction of travel of the vehiclesystem.

In one example, the one or more sensors include an optical sensororiented toward the route in a direction that is opposite a direction oftravel of the vehicle system.

In one example, the one or more processors are configured to identifythe reference location by identifying an intersection between a locationon the route and a reference line in the sensor data, the reference linerepresenting a fixed distance from the one or more sensors.

In one example, the one or more processors are configured to identifythe location of interest by identifying an intersection between thelocation on the route used to determine the reference location and areference line in the sensor data.

In one example, the difference between the reference location and thelocation of interest represents a change in trajectory of the route atdifferent locations of the one or more sensors along the route.

In one example, the one or more processors also are configured todetermine a nominal degree of curvature of the route based on the degreeof curvature that is determined.

In one example, the one or more processors are configured to determinethe degree of curvature of the route one or more additional times. Thenominal degree of curvature is determined as a moving average of thedegrees of curvature that are determined.

In one example, the one or more processors are configured to determine arate of change in the nominal degree of curvature, compare the rate ofchange that is determined to a designated threshold, and change a valueof the nominal degree of curvature responsive to the rate of changeexceeding the designated threshold.

In one example, the one or more processors are configured to identify amisalignment in the route based on the degree of curvature that isdetermined.

In one example, the misalignment is a thermal misalignment of aconductive portion of the route.

In one example, the one or more processors are configured to determine adeviation of the degree of curvature from the nominal degree ofcurvature. The misalignment is determined based on the deviation.

In one example, the one or more processors are configured to determinethe misalignment responsive to the deviation exceeding a designatedthreshold.

In one example, the one or more processors are configured to determinethe misalignment responsive to a sum of the deviation and one or morepreviously determined deviations exceeding a designated threshold.

In one example, the one or more processors are configured to determinethe misalignment responsive to an average of the deviation and one ormore previously determined deviations exceeding a designated threshold.

In one example, the one or more processors are configured to implementone or more responsive actions responsive to determining themisalignment in the route.

In one example, the one or more responsive actions is one or more ofautomatically slowing or stopping movement of the vehicle system,communicating a warning signal to another vehicle traveling toward themisalignment in the route, communicating the warning signal to anothervehicle scheduled to travel toward the misalignment in the route,remotely controlling movement of another vehicle traveling toward themisalignment to alter the movement of the other vehicle, remotelycontrolling a switch in the route to prevent another vehicle fromtraveling over the misalignment, and/or communicating a signal to arepair facility to direct repair of the route at the misalignment.

In one embodiment, a method (e.g., for inspecting a route) includesidentifying a reference location in sensor data provided by one or moresensors onboard a vehicle system. The reference location is identifiedalong a route being traveled by the vehicle system. The method alsoincludes identifying a location of interest in subsequent sensor dataprovided by the one or more sensors. The location of interest isidentified along the route being traveled by the vehicle system. Themethod also includes determining a degree of curvature in the routebased on a difference between the reference location and the location ofinterest.

In one example, the sensor data and the subsequent sensor data includeone or more of images, a video, or video frames of the route.

In one example, the one or more sensors include a sensor oriented towardthe route along a direction of travel of the vehicle system.

In one example, the one or more sensors include a sensor oriented towardthe route in a direction that is opposite a direction of travel of thevehicle system.

In one example, identifying the reference location includes identifyingan intersection between a location on the route and a reference line inthe sensor data, the reference line representing a fixed distance fromthe one or more sensors.

In one example, identifying the location of interest includesidentifying an intersection between the location on the route used todetermine the reference location and a reference line in the sensordata.

In one example, the difference between the reference location and thelocation of interest represents a change in trajectory of the route atdifferent locations of the one or more sensors along the route.

In one example, the method also includes determining a nominal degree ofcurvature of the route based on the degree of curvature that isdetermined.

In one example, the method also includes determining the degree ofcurvature of the route one or more additional times, where the nominaldegree of curvature is determined as a moving average of the degrees ofcurvature that are determined.

In one example, the method also includes determining a rate of change inthe nominal degree of curvature, comparing the rate of change that isdetermined to a designated threshold, and changing a value of thenominal degree of curvature responsive to the rate of change exceedingthe designated threshold.

In one example, the method also includes determining a misalignment inthe route based on the degree of curvature that is determined.

In one example, the misalignment is a thermal misalignment of aconductive portion of the route.

In one example, the method also includes determining a deviation of thedegree of curvature from the nominal degree of curvature, where themisalignment is determined based on the deviation.

In one example, the misalignment is determined responsive to thedeviation exceeding a designated threshold.

In one example, the misalignment is determined responsive to a sum ofthe deviation and one or more previously determined deviations exceedinga designated threshold.

In one example, the misalignment is determined responsive to an averageof the deviation and one or more previously determined deviationsexceeding a designated threshold.

In one example, the method also includes implementing one or moreresponsive actions responsive to determining the misalignment in theroute.

In one example, the one or more responsive actions is one or more ofautomatically slowing or stopping movement of the vehicle system,communicating a warning signal to another vehicle traveling toward themisalignment in the route, communicating the warning signal to anothervehicle scheduled to travel toward the misalignment in the route,remotely controlling movement of another vehicle traveling toward themisalignment to alter the movement of the other vehicle, remotelycontrolling a switch in the route to prevent another vehicle fromtraveling over the misalignment, and/or communicating a signal to arepair facility to direct repair of the route at the misalignment.

The inventive subject matter described herein also can inspect a routefor changes to the route at a location after a vehicle system travelsover the location. For example, the inspection systems described hereincan examine the route at a location of interest from onboard the vehiclesystem before and after the vehicle system moves over the location ofinterest. Based on differences between before and after the vehiclesystem moves over the location of interest, the inspection system candetermine if the condition or state of the route has changed. Forexample, the inspection systems can determine whether passage of thevehicle system has bent a rail in the route, formed or enlarged apothole in a road, failed to fully clean up debris in the route (wherethe vehicle system is equipped to clean debris from the route), formedruts or other indentations in the route, etc. In one example, theinspection system and method can obtain image data (e.g., one or moreimages, videos, video frames, etc.) of a location of interest in theroute before the vehicle system having the inspection system onboardmoves over or through the location of interest. The inspection systemand method can obtain additional image data of the same location ofinterest in the route after the vehicle system moves over or through thelocation of interest. The image data from prior to vehicle systempassage over the location of interest and after vehicle system passageover the location of interest can be compared with each other toidentify any changes in the state or condition of the route at thelocation of interest due to passage of the vehicle system.

While some embodiments of the subject matter described herein aredescribed in connection with rail vehicles, not all embodiments of theinventive subject matter are limited to rail vehicles traveling ontracks formed from one or more rails. For example, one or moreembodiments of the inspection systems and methods described herein canbe used in connection with automobiles, buses, trucks, or the like, todetermine whether passage of the vehicles over a route created orenlarged a pothole, crack, or other damage; whether passage of astreet-cleaning or street-sweeping vehicle fully cleaned debris from thestreet or left some debris in the street; whether passage of a miningvehicle, agricultural vehicle, or other vehicle traveling on a non-pavedroute formed ruts or other indentations in the route from passage overthe route; and the like.

FIG. 15 illustrates another example of the vehicle system 502 travelingon the route 514 prior to moving over a location of interest 1500 in theroute 514. FIG. 16 illustrates the vehicle system 502 traveling on theroute 514 after moving over the location of interest 1500 in the route514. As described above in connection with FIGS. 5 and 6, the inspectionsystem can include a leading sensor 504 and a trailing sensor 506relative to a direction of movement 516 of the vehicle system. Each ofthese sensors can be an optical sensor. While these leading and trailingsensors are shown as being disposed on different vehicles of the vehiclesystem in FIG. 5, alternatively, the leading and trailing sensors may bedisposed onboard a single vehicle (e.g., where the vehicle system isformed from a single vehicle), as shown in FIG. 15.

Each of the leading and trailing sensors can have a field of view, whichrepresents the areas or volumes captured or represented by data outputby the sensors. For example, the leading sensor can be a camera, LiDARsystem, infrared camera, other type of infrared sensor, or the like,having a forward field of view 1502. The field of view of the leadingsensor can be referred to as a leading field of view as this field ofview is ahead of the vehicle system. Data output by the leading sensor(e.g., images and/or videos) can represent objects, events, etc.,located ahead of the vehicle system along the direction of movement ofthe vehicle system. The trailing sensor can be a camera, LiDAR system,infrared camera, other type of infrared sensor, or the like, having arearward field of view 1504. The field of view of the trailing sensorcan be referred to as a rearward field of view as this field of view isbehind of the vehicle system. Data output by the trailing sensor (e.g.,images and/or videos) can represent objects, events, etc., locatedbehind the vehicle system along the direction of movement of the vehiclesystem.

In operation, the controller of the inspection system obtains image dataof the route from the leading sensor as the vehicle system moves alongthe route. This image data can depict a segment of the route prior topassage of the vehicle system over the segment of the route. Thecontroller also can obtain image data of the route from the trailingsensor as the vehicle system moves along the route. After the vehiclesystem moves over a segment previously captured in the image data outputby the leading sensor, the image data output by the trailing sensor canrepresent the same segment of the route but in the field of view of thetrailing sensor.

The controller can compare the image data output by the leading andtrailing sensors to determine whether a change in the route hasoccurred. For example, the controller can determine whether a shape orother appearance of the route at the same location (e.g., a location ofinterest) in the image data from the leading sensor has changed in theimage data from the trailing sensor. A change in the image data mayindicate that the state or condition of the route has changed due (atleast in part) to movement of the vehicle system over the location inthe route.

FIG. 17 illustrates one example of image data 1700 output by the leadingsensor 504 and FIG. 18 illustrates one example of image data 1800 outputby the trailing sensor 506. The image data 1700, 1800 each show the samesegment of the route 514 from different viewpoints. For example, theimage data 1700 can represent the segment of the route in the field ofview of the leading sensor as the vehicle system approaches the segmentof the route. The image data 1800 can represent the same segment of theroute in the field of view of the trailing sensor. As a result, theimage data 1700, 1800 can be mirror images of each other (or approximatemirror images of each other, subject to changes in the route caused atleast in part by passage of the vehicle system).

The controller can compare the image data from the leading and trailingsensors to determine whether the state or condition of the route withinthe segment changed upon travel of the vehicle system over or throughthe segment. For example, the controller can perform a translation ofthe image data provided by one of the leading or trailing sensor tocreate a mirror image version of the image data. FIG. 19 illustrates oneexample of a mirror translation 1900 of the image data 1800 output bythe trailing sensor. The controller can create the mirror translation byflipping or otherwise moving pixels or other sub-parts of the image data1800 about or across an axis, such as the left edge of the image data1800.

The controller can then compare the image data from the leading andtrailing sensors, such as by identifying differences between the imagedata from the leading sensor and the mirror image of the image data fromthe trailing sensor, identifying differences between the image data fromthe trailing sensor and the mirror image of the image data from theleading sensor, by overlaying the image data from one sensor onto themirror image of the image data from the other sensor, by overlaying themirror image of the image data from one sensor onto the image data fromthe other sensor, and the like. In the illustrated example, the routeappears the same (or nearly the same as) in the image data from theleading sensor as the mirror image data of the trailing sensor. This canindicate that the state or condition of the route has not changed frommovement of the vehicle system over the same segment of the route.

FIG. 20 illustrates another example of image data 2000 that may beoutput by the trailing sensor 506 after the vehicle system has traveledover the segment of the route depicted in the image data 1700 output bythe leading sensor. FIG. 21 illustrates a mirror translation 2100 of theimage data 2000 shown in FIG. 20. As described above, the controller cancompare the image data 1700 from the leading sensor with the mirrortranslation 2100 of the image data 2000 from the trailing sensor toidentify changes in the route. Alternatively, the controller can comparethe image data 2000 from the trailing sensor with a mirror translationof the image data 1700 from the leading sensor to identify changes inthe route.

FIG. 22 illustrates an overlay 2200 of the mirror translation 2100 ofthe image data 2000 from the trailing sensor onto the image data 1700from the leading sensor. The controller can examine the image dataand/or mirror translation to identify differences 2102 between the imagedata and the mirror translation. These differences indicate a change inthe route, such as an outward bend in one rail of the route.Alternatively, the differences can indicate the formation or expansionof a rut, pothole, crack, or indentation in the route; debris that wasnot removed from the route (e.g., an uncleaned area of the route); orthe like.

The controller may use machine learning to identify the changes in theroute. For example, the controller may repeatedly identify locationswhere a change is detected and locations where a change is not detected.Information input into the controller (e.g., by an operator or routepersonnel) can confirm or refute whether a change occurred at one ormore of these locations. Based on the accuracy or inaccuracy of thecontroller in identifying where the changes actually occurred and wherethe controller accurately and/or inaccurately identified changes, thecontroller can learn over time how to better identify changes in theroute. Alternatively, the controller may use one or more othertechniques to determine whether the route has changed or has beenmodified as described herein.

The location where the change in the route is identified can be referredto as a location of interest in the route. Responsive to detecting oridentifying a change in the state of the route at such a location ofinterest, the controller can implement or perform one or more responsiveactions. As one example, the controller can communicate an advisorysignal to one or more off-board locations.

In one embodiment, the output device 610 shown in FIG. 6 can representor include a communication device that communicates with the off-boardlocations. This output device can include transceiving circuitry andassociated hardware, such as modems, antennas, or the like. Thecontroller can direct the output device to wirelessly communicate (e.g.,broadcast and/or transmit) the advisory signal responsive to detectingthe change in the route from the image data before and after the vehiclesystem traveled over the route. This advisory signal can be communicatedto an off-board protection or safety system that communicates withseveral vehicle systems to restrict where and/or when the vehiclesystems are permitted to travel. For example, the advisory signal can becommunicated to a positive protection system that communicates positivesignals to vehicle systems traveling within an area associated with thepositive protection system. These positive signals indicate that avehicle system can enter into an upcoming segment of a route. If acontroller onboard the vehicle system does not receive a positive signalfrom the protection system for an upcoming segment of the route, thenthe controller may prevent the vehicle system from entering into theupcoming segment. For example, the controller can automatically controlthe propulsion system from propelling the vehicle system into theupcoming segment, automatically control the brake system to stop thevehicle system from entering into the upcoming segment, automaticallysteer the vehicle system in a direction that prevents the vehicle systemfrom entering into the upcoming segment, etc. Alternatively, thecontroller of the vehicle system can prevent the vehicle system fromentering into an upcoming segment unless a positive signal is receivedby preventing commands input by the operator of the vehicle system fromcontrolling the propulsion system and/or brake system from moving thevehicle system into the upcoming segment (unless and/or until thepositive signal is received). One example of such a positive controlsystem is a positive train control system.

The protection system may be a negative protection system thatcommunicates negative signals to vehicle systems. These signals arecommunicated to indicate that a vehicle system cannot enter into anupcoming segment of a route. If a controller onboard the vehicle systemdoes not receive a negative signal from the protection system for anupcoming segment of the route, then the controller allows the vehiclesystem to enter into the upcoming segment. The controller may onlyprevent the vehicle system from entering into the upcoming segment ifthe negative protection system sends a negative signal (indicating thatthe vehicle system cannot enter into the upcoming route segment).

The controller onboard the vehicle system can communicate the advisorysignal to the positive or negative protection system responsive toidentifying the change in the route. The protection system can then usethis change in the route to control where other vehicle systems areallowed to travel. For example, the protection system can communicatemovement authorities to the vehicle systems to prevent other vehiclesystems from traveling over or through the segment of the route wherethe change in the route was detected, can reduce the speeds (e.g., speedlimits) at which the vehicle systems are permitted to travel over orthrough the segment of the route where the change in the route wasdetected, or the like.

Optionally, the controller can communicate the advisory signal to theprotection system responsive to not identifying or detecting a change inthe route. For example, the controller can inform the protection systemthat the route does not appear to have changed states. The protectionsystem can use this information communicated via the advisory signal toallow other vehicle systems to travel through the segment in which nochange was detected and/or to allow other vehicle systems to travelthrough the segment in which no change was detected without anyreduction in speed limit(s). For example, the vehicle system may receivea communication from the protection system that modifies or eliminates areduced speed limit responsive to the off-board protection system beingnotified that the change in the route has not occurred.

The controller can communicate the advisory signal to an off-boardlocation or system to request inspection and/or repair of the route. Forexample, responsive to detecting a change in the route, the controllercan request that personnel at a dispatch facility, repair facility, orthe like, to travel to the location where the change in the route wasdetected to inspect and/or repair the route. The advisory signal canindicate the location of interest (where the change was detected) and,optionally, the time at which the change was detected (or when the imagedata used to identify the change was obtained or generated).

The controller can communicate the advisory signal to other vehiclesystems to notify the vehicle systems of detection of the change in theroute and/or the lack of detecting a change in the route. For example,the controller can transmit the advisory signal to individual vehiclesystems or broadcast the vehicle system to vehicle systems withincommunication range. The advisory signal can inform the vehicle systemsof the location and/or date at which the change in the route was or wasnot detected. The vehicle systems, in turn, can use this information tocontrol where and/or how the vehicle systems move (e.g., by slowingtravel through the location where the change in the route was detected,by changing which route the vehicle systems travel on, etc.).

Optionally, the controller can implement one or more responsive actionswith the vehicle system in which the controller is disposed responsiveto detecting a change in the route. For example, the controller canrestrict how fast the vehicle system is moving along the routeresponsive to determining that travel of the vehicle system may havecaused a change in the route. This can help prevent further damage orchanges to the route.

In one embodiment, the controller may obtain and/or compare the imagedata responsive to one or more triggers or trigger events occurring. Asone example, the route may be more likely to be deformed by movement ofthe vehicle system in elevated ambient temperatures. Therefore, atrigger event may be an ambient temperature increasing above a thresholdlimit. One or more of the sensors onboard the vehicle system can includea temperature sensor. For example, one or more of the sensors 504, 506(or an additional sensor) may include a thermometer, thermocouple, orthe like, that measures an ambient temperature outside of the vehiclesystem. Alternatively, the temperature may not be measured by an onboardsensor, but may be reported or otherwise communicated to the controllerfrom an off-board location or system, such as a weather reportingsystem. The controller can examine the ambient temperatures duringmovement of the vehicle system to determine whether the ambienttemperature exceeds a designated elevated temperature threshold orlimit. Responsive to the ambient temperature exceeding this threshold orlimit, the controller may obtain and/or compare the image data todetermine whether the route is changed due at least in part to movementof the vehicle system over the route. Another trigger or trigger eventcan be operator input. For example, the controller can obtain and/orcompare the image data responsive to an operator providing inputrequesting the inspection of the route and/or indicating an elevatedambient temperature. Another trigger or trigger event can be a signalreceived from an off-board source, such as from a protection system.

Another trigger or trigger event may be used to cause the trailingoptical sensor to obtain the image data based on location informationand/or moving information. This location information can be a distancethat separates the leading optical sensor from the trailing opticalsensor. For example, the location information can be a distance measuredalong the path of the route from the leading optical sensor to thetrailing optical sensor. The moving information can be a speed at whichthe vehicle system is moving. The controller can determine when totrigger the trailing optical sensor to obtain the image data following atime at which the leading optical sensor based on the distance and themoving speed. For example, the controller can calculate a period of timebetween when the field of views of the leading and trailing opticalsensors will encompass the same location of interest in the route basedon the distance between sensors and the moving speed. The controller canthen trigger the trailing optical sensor to obtain the image data of theroute following expiration of this defined period of time following thetime at which the leading optical sensor obtained the image data.

In one embodiment, each or at least one of the optical sensors mayobtain a set or series of images of the route, such as several separateimages and/or frames of a video. The controller can then compare atleast some of the images in the set obtained by the leading opticalsensor with at least some of the images in the set obtained by thetrailing optical sensor to determine whether a change in the route hasoccurred. The controller can determine which of the images in the setsof images to compare with each other based on the location informationand/or moving information described above. This can ensure that thecontroller is comparing the image data from the leading optical sensorwith the image data from the trailing optical sensor that show the samesegment of the route.

The controller may examine the route based on the image data obtained bythe leading and/or trailing optical sensors and using data from one ormore other sensors. These other sensors may be included in or may beseparate from the sensors 504, 506. The other sensors may be non-opticalsensors, such as impact and/or vibration sensors. The data from theseother sensors may confirm or refute the detection of a change in theroute from the image data. For example, a difference in the image datamay indicate a change in a segment of the route and vibrations measuredby an accelerometer during movement of the vehicle system over the sameroute segment may confirm this change in the route segment. As anotherexample, a difference in the image data may indicate a change in asegment of the route, but vibrations measured by an accelerometer duringmovement of the vehicle system over the same route segment may refutethis change in the route segment.

The controller optionally can examine image data of the same segment ofthe route from different passages of the vehicle system over the routesegment. For example, the changes in the route during a single passageof the route may be relatively small, thereby increasing the likelihoodthat a change in the route is missed by the controller. The controllercan store or access image data acquired during other travels of thevehicle system over the route segment (during prior days, weeks, months,or years). The controller can compare these previously obtained sets ofimage data with each other and/or more recently obtained image data todetermine whether the route is changing over time. The controller cancompare image data obtained at different times with each other toidentify the changes, as described above.

The controller also can obtain other information about the vehiclesystem and use this information in determining whether a difference inthe image data indicates a change in the route. For example, thecontroller can determine an operational state of one or more vehicles inthe vehicle system, such as whether vehicles are in high or low gear,the speed at which the vehicle or vehicle system is moving, etc. Asanother example, the controller can examine a manifest of cargo carriedby the vehicle system (or absence thereof) to determine whether thevehicle system is loaded or unloaded, and/or the weight of the vehiclesystem. This additional information can be used to determine whether theroute has changed. For example, if the difference between the image datais relatively small or minor, but the operational information indicatesthat a very heavy vehicle system was traveling at a high gear over theroute, the controller may be more likely to determine that the route haschanged. As another example, if the difference between the image data isrelatively small or minor, and the operational information indicatesthat a lighter vehicle system was traveling at a lower gear over theroute, the controller may be less likely to determine that the route haschanged.

The controller can determine a health status of the vehicles in thevehicle system (propulsion-generating and/or non-propulsion-generatingvehicles), such as the conditions of wheels of the vehicle system from aprior maintenance check or inspection, the amount of usage (e.g.,miles), etc. This additional information can be used to determinewhether the route has changed. For example, if the difference betweenthe image data is relatively small or minor, but the operationalinformation indicates that the health status of the vehicles is poor,the controller may be more likely to determine that the route haschanged. As another example, if the difference between the image data isrelatively small or minor, and the health status indicates less wear onthe wheels, the controller may be less likely to determine that theroute has changed.

FIG. 23 illustrates a flowchart of one example of a method 2300 forinspecting a route. The method 2300 can represent operations performedby and/or under direction of the controller to inspect a segment of aroute before and after a vehicle system travels over the route segment.Alternatively, the operations can be performed by a controller that isoff-board the vehicle system. For example, the image data can becompared and examined off-board the vehicle system to identify changesin the route.

At 2302, image data of an upcoming segment of a route is obtained. Theimage data can be one or more images and/or videos of an area ahead of avehicle system as the vehicle system moves along the route. At 2304, thevehicle system moves over the segment of the route that is shown in theimage(s) and/or video(s) obtained at 2302. At 2306, image data of thesame segment of the route is obtained after the vehicle system passesover the segment of the route. For example, one or more images and/orvideos of an area behind the vehicle system can be obtained such thatthe segment of the route depicted in the image data obtained at 2302from ahead of the vehicle system also is depicted in the image dataobtained at 2306 from behind the vehicle system.

At 2308, a determination is made as to whether one or more differencesbetween the image data exists. The difference(s) can be changes to theroute caused (at least in part) by movement of the vehicle system overthe route. For example, the comparison may show that a rail of the routehas moved, that a rut was formed (or widened or deepened) in the routeby the vehicle system, that a pothole was formed (or widened ordeepened) in the route by the vehicle system, that a crack was formed(or widened or deepened) in the route by the vehicle system, that debriswas not fully removed from the route, or the like.

If a difference in the image data is identified, then the difference mayindicate that the route was changed during passage of the vehicle systemover the imaged segment of the route. As a result, flow of the method2300 can proceed toward 2310. But, if a difference in the image data isnot identified, then the absence of the difference may indicate that theroute did not change from movement of the vehicle system over the imagedroute segment. As a result, flow of the method 2300 can proceed toward2314.

At 2310, a change in the route is identified in the segment that wasimaged. This change can be a bending of a rail, digging of a rut,creation or enlarging of a pothole or crack, etc. At 2312, one or moreresponsive actions are implemented. The responsive actions can includecommunicating an advisory signal to off-board systems, communicating anadvisory signal to other vehicle systems, slowing movement of thevehicle system, or the like, as described herein. Flow of the method2300 can then return toward 2302 or may terminate.

If the difference in the image data is not identified at 2308, then theabsence of the difference may indicate that the route did not changefrom movement of the vehicle system over the imaged route segment at2314. At 2316, one or more responsive actions optionally may beimplemented. For example, an advisory signal may be communicated to oneor more off-board systems to notify the systems of the absence of achange in the route, as described above.

In any of the embodiments herein, the vehicle system in conjunction withwhich the system (e.g., route inspection system) is implemented may be adrone, other aerial vehicle, or other autonomous or remote controlledvehicle. For example, in one particular embodiment, a remote controlledor autonomous aerial drone (e.g., such as a quadcopter) is outfittedwith one or more cameras or other optical sensors or other sensors thatare configured to output sensor data of a route along which the dronetravels, such as above a railway. The drone is controlled and/orconfigured to follow a path along the route in a manner by which thesensor data is suitable for use in determining a degree of curvature inthe route based on a difference between a reference location and alocation of interest, as explained herein. For example, if the route isa railway having two nominally parallel rails (i.e., for normaloperation in an undamaged condition, the rails are configured to beparallel), the drone may be controlled and/or configured to follow apath along the midpoint between the rails, or to travel above and alongone of the rails (e.g., a designated or chosen one of the rails), or totravel along one of the rails but a designated set lateral distance tothe left or right of the rail. The one or more processors of the routeinspection system may be deployed on board the autonomous or remotecontrolled vehicle, and/or the autonomous or remote controlled vehiclemay transmit the sensor data to an off-board location where the one ormore processors are located. Alternatively, one or more of theprocessors may be deployed on board the autonomous or remote controlledvehicle and one or more of the processors may be located in an off-boardlocation. The off-board processor(s) may be located in a fixed, centrallocation (such as a dispatch or maintenance facility), and/or they maybe located on another vehicle or vehicle system. For example, anautonomous or remote controlled vehicle may be carried by a secondvehicle or vehicle system (e.g., a drone carried by a locomotive), withthe autonomous or remote controlled vehicle being dispatched from thesecond vehicle periodically for inspection purposes, e.g., ahead of thesecond vehicle or vehicle system traveling along a route. In such anembodiment, one or more of the route inspection system processors may beon board the second vehicle or vehicle system, with the autonomous orremote controlled vehicle configured to transmit sensor data back to thesecond vehicle or vehicle system for processing and use by the secondvehicle or vehicle system (e.g., for control purposes).

In at least one embodiment, the control system (such as one or morecontrollers described herein) may have a local data collection systemdeployed that may use machine learning to enable derivation-basedlearning outcomes. The controller may learn from and make decisions on aset of data (including data provided by the various sensors), by makingdata-driven predictions and adapting according to the set of data. Inembodiments, machine learning may involve performing a plurality ofmachine learning tasks by machine learning systems, such as supervisedlearning, unsupervised learning, and reinforcement learning. Supervisedlearning may include presenting a set of example inputs and desiredoutputs to the machine learning systems. Unsupervised learning mayinclude the learning algorithm structuring its input by methods such aspattern detection and/or feature learning. Reinforcement learning mayinclude the machine learning systems performing in a dynamic environmentand then providing feedback about correct and incorrect decisions. Inexamples, machine learning may include a plurality of other tasks basedon an output of the machine learning system. In examples, the tasks maybe machine learning problems such as classification, regression,clustering, density estimation, dimensionality reduction, anomalydetection, and the like. In examples, machine learning may include aplurality of mathematical and statistical techniques. In examples, themany types of machine learning algorithms may include decision treebased learning, association rule learning, deep learning, artificialneural networks, genetic learning algorithms, inductive logicprogramming, support vector machines (SVMs), Bayesian network,reinforcement learning, representation learning, rule-based machinelearning, sparse dictionary learning, similarity and metric learning,learning classifier systems (LCS), logistic regression, random forest,K-Means, gradient boost, K-nearest neighbors (KNN), a priori algorithms,and the like. In embodiments, certain machine learning algorithms may beused (e.g., for solving both constrained and unconstrained optimizationproblems that may be based on natural selection). In an example, thealgorithm may be used to address problems of mixed integer programming,where some components restricted to being integer-valued. Algorithms andmachine learning techniques and systems may be used in computationalintelligence systems, computer vision, Natural Language Processing(NLP), recommender systems, reinforcement learning, building graphicalmodels, and the like. In an example, machine learning may be used forvehicle performance and behavior analytics, and the like.

In at least one embodiment, the control system may include a policyengine that may apply one or more policies. These policies may be basedat least in part on characteristics of a given item of equipment orenvironment. With respect to control policies, a neural network canreceive input of a number of environmental and task-related parameters.These parameters may include an identification of a determined trip planfor a vehicle group, data from various sensors, and location and/orposition data. The neural network can be trained to generate an outputbased on these inputs, with the output representing an action orsequence of actions that the vehicle group should take to accomplish thetrip plan. During operation of one embodiment, a determination can occurby processing the inputs through the parameters of the neural network togenerate a value at the output node designating that action as thedesired action. This action may translate into a signal that causes thevehicle to operate. This may be accomplished via back-propagation, feedforward processes, closed loop feedback, or open loop feedback.Alternatively, rather than using backpropagation, the machine learningsystem of the controller may use evolution strategies techniques to tunevarious parameters of the artificial neural network. The controller mayuse neural network architectures with functions that may not always besolvable using backpropagation, for example functions that arenon-convex. In one embodiment, the neural network has a set ofparameters representing weights of its node connections. A number ofcopies of this network are generated and then different adjustments tothe parameters are made, and simulations are done. Once the output fromthe various models are obtained, they may be evaluated on theirperformance using a determined success metric. The best model isselected, and the vehicle controller executes that plan to achieve thedesired input data to mirror the predicted best outcome scenario.Additionally, the success metric may be a combination of the optimizedoutcomes, which may be weighed relative to each other.

In one embodiment, a method includes obtaining first image data of aroute at a location of interest from a first optical sensor disposedonboard a vehicle system moving along the route. The first image datadepicts the route at the location of interest prior to passage of thevehicle system over the route at the location of interest. The methodalso includes obtaining second image data of the route at the locationof interest from a second optical sensor disposed onboard the vehiclesystem. The second image data depicts the route at the location ofinterest after passage of the vehicle system over the route at thelocation of interest. The method also includes determining whether achange in the route has occurred at the location of interest bycomparing the first image data with the second image data.

Optionally, the method also can include determining whether an ambienttemperature exceeds a designated upper limit. Obtaining one or more ofthe first image data or the second image data can occur responsive todetermining that the ambient temperature exceeds the designated upperlimit.

Optionally, the method also can include determining the ambienttemperature from a sensor onboard the vehicle system.

Optionally, the method also can include determining the ambienttemperature from an off-board system that is off-board the vehiclesystem.

Optionally, obtaining the first image data occurs from the first opticalsensor disposed at a leading end of the vehicle system and obtaining thesecond image data occurs from the second optical sensor disposed at anopposite, trailing end of the vehicle system.

Optionally, the vehicle system is formed from at least a leading vehicleand a trailing vehicle, and obtaining the first image data occurs fromthe first optical sensor disposed on the leading vehicle and obtainingthe second image data occurs from the second optical sensor disposed onthe trailing vehicle.

Optionally, obtaining the second image data occurs responsive to adefined period of time expiring following obtaining the first imagedata, the defined period of time based on a distance between the firstoptical sensor and the second optical sensor and a speed at which thevehicle system is moving.

Optionally, determining whether the change in the route has occurredincludes obtaining a mirror image of the first image data or the secondimage data, and comparing the mirror image with the first image data orthe second image data.

Optionally, determining whether the change in the route has occurredincludes determining a reference location in the first image data andthe second image data and determining a difference between the locationof interest and the reference location. Determining whether the changein the route has occurred can be based on the difference.

Optionally, obtaining the first image data includes obtaining a firstset of image frames of the route and obtaining the second image dataincludes obtaining a second set of image frames of the route, anddetermining whether the change in the route has occurred includescomparing the first set of the image frames with the second set of theimage frames.

Optionally, the vehicle system is a first vehicle system, and the methodalso can include notifying an off-board protection system of the changein the route. The off-board protection system can issue a movementauthority to one or more additional vehicle systems to limit a speed atwhich the one or more additional vehicle systems move over the locationof interest.

Optionally, the vehicle system moves along the route according to areduced speed limit issued by an off-board protection system, and themethod also can include notifying the off-board protection system thatthe change in the route has not occurred, and receiving a modificationor elimination of the reduced speed limit from the off-board protectionsystem responsive to the off-board protection system being notified thatthe change has not occurred.

Optionally, the method also can include communicating a request to anoff-board system to one or more of inspect or repair the route at thelocation of interest responsive to determining that the change in theroute has occurred.

Optionally, the method also can include restricting a speed at which thevehicle system moves along the route responsive to determining that thechange in the route has occurred.

Optionally, the change in the route includes one or more of a bend in arail of a track, an indentation in the route, a rut in the route, apothole in the route, or an uncleaned area of the route.

In one embodiment, a system includes a controller configured to obtainfirst image data of a route at a location of interest from a firstoptical sensor disposed onboard a vehicle system moving along the route.The first image data depicts the route at the location of interest priorto passage of the vehicle system over the route at the location ofinterest. The controller also is configured to obtain second image dataof the route at the location of interest from a second optical sensordisposed onboard the vehicle system. Teh second image data depicts theroute at the location of interest after passage of the vehicle systemover the route at the location of interest. The controller is configuredto determine whether a change in the route has occurred at the locationof interest by comparing the first image data with the second imagedata.

Optionally, the controller is configured to determine whether an ambienttemperature exceeds a designated upper limit, the controller configuredto obtain one or more of the first image data or the second image dataresponsive to determining that the ambient temperature exceeds thedesignated upper limit.

Optionally, the controller is configured to obtain the first image datafrom the first optical sensor disposed at a leading end of the vehiclesystem and the second image data from the second optical sensor disposedat an opposite, trailing end of the vehicle system.

In one embodiment, a system includes a controller configured to examineimage data of a common segment of a route obtained before and afterpassage of a vehicle system over the common segment of the route. Thecontroller is configured to determine one or more differences betweenthe image data and to determine that the common segment of the route isdamaged by passage of the vehicle system based on the one or moredifferences that are determined.

Optionally, the controller is configured to determine the one or moredifferences by comparing a first set of the image data obtained ahead ofa direction of movement of the vehicle system with a second set of theimage data obtained behind the direction of movement of the vehiclesystem.

The foregoing description of certain embodiments of the inventivesubject matter will be better understood when read in conjunction withthe appended drawings. To the extent that the figures illustratediagrams of the functional blocks of various embodiments, the functionalblocks are not necessarily indicative of the division between hardwarecircuitry. Thus, for example, one or more of the functional blocks (forexample, processors or memories) may be implemented in a single piece ofhardware (for example, a general purpose signal processor,microcontroller, random access memory, hard disk, and the like).Similarly, the programs may be stand-alone programs, may be incorporatedas subroutines in an operating system, may be functions in an installedsoftware package, and the like. The various embodiments are not limitedto the arrangements and instrumentality shown in the drawings.

The above description is illustrative and not restrictive. For example,the above-described embodiments (and/or aspects thereof) may be used incombination with each other. In addition, many modifications may be madeto adapt a particular situation or material to the teachings of theinventive subject matter without departing from its scope. While thedimensions and types of materials described herein are intended todefine the parameters of the inventive subject matter, they are by nomeans limiting and are example embodiments. Other embodiments may beapparent to one of ordinary skill in the art upon reviewing the abovedescription. The scope of the inventive subject matter should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled.

In the appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112(f), unless and until such claim limitations expresslyuse the phrase “means for” followed by a statement of function void offurther structure. And, as used herein, an element or step recited inthe singular and proceeded with the word “a” or “an” should beunderstood as not excluding plural of said elements or steps, unlesssuch exclusion is explicitly stated. Furthermore, references to “oneembodiment” of the inventive subject matter are not intended to beinterpreted as excluding the existence of additional embodiments thatalso incorporate the recited features. Moreover, unless explicitlystated to the contrary, embodiments “comprising,” “including,” or“having” an element or a plurality of elements having a particularproperty may include additional such elements not having that property.

This written description uses examples to disclose several embodimentsof the inventive subject matter and also to enable a person of ordinaryskill in the art to practice the embodiments of the inventive subjectmatter, including making and using any devices or systems and performingany incorporated methods. The patentable scope of the inventive subjectmatter is defined by the claims, and may include other examples thatoccur to those of ordinary skill in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims.

What is claimed is:
 1. A method comprising: obtaining first image dataof a route at a location of interest from a first optical sensordisposed onboard a vehicle system; and obtaining second image data ofthe route at the location of interest from a second optical sensordisposed onboard the vehicle system, the second image data depicting theroute at the location of interest after passage of the vehicle systemover the route at the location of interest, wherein obtaining the secondimage data occurs responsive to a defined period of time expiringfollowing obtaining the first image data, the defined period of timebased on a distance between the first optical sensor and the secondoptical sensor and a speed at which the vehicle system is moving.
 2. Themethod of claim 1, wherein the first image data depicts the route at thelocation of interest prior to passage of the vehicle system over theroute at the location of interest.
 3. The method of claim 1, furthercomprising determining whether a change in the route has occurred at thelocation of interest by comparing the first image data with the secondimage data.
 4. The method of claim 1, further comprising: determiningwhether an ambient temperature exceeds a designated upper limit, whereinobtaining one or more of the first image data or the second image dataoccurs responsive to determining that the ambient temperature exceedsthe designated upper limit.
 5. The method of claim 4, furthercomprising: determining the ambient temperature from a sensor onboardthe vehicle system.
 6. The method of claim 4, further comprising:determining the ambient temperature from an off-board system that isoff-board the vehicle system.
 7. The method of claim 1, whereinobtaining the first image data occurs from the first optical sensordisposed at a leading end of the vehicle system and obtaining the secondimage data occurs from the second optical sensor disposed at anopposite, trailing end of the vehicle system.
 8. The method of claim 7,wherein the vehicle system is formed from at least a leading vehicle anda trailing vehicle, and obtaining the first image data occurs from thefirst optical sensor disposed on the leading vehicle and obtaining thesecond image data occurs from the second optical sensor disposed on thetrailing vehicle.
 9. The method of claim 1, wherein determining whetherthe change in the route has occurred includes obtaining a mirror imageof the first image data or the second image data, and comparing themirror image with the first image data or the second image data.
 10. Themethod of claim 1, wherein determining whether the change in the routehas occurred includes determining a reference location in the firstimage data and the second image data and determining a differencebetween the location of interest and the reference location, whereindetermining whether the change in the route has occurred is based on thedifference.
 11. The method of claim 1, wherein obtaining the first imagedata includes obtaining a first set of image frames of the route andobtaining the second image data includes obtaining a second set of imageframes of the route, and determining whether the change in the route hasoccurred includes comparing the first set of the image frames with thesecond set of the image frames.
 12. The method of claim 1, wherein thevehicle system is a first vehicle system, and further comprising:notifying an off-board protection system of the change in the route, theoff-board protection system issuing a movement authority to one or moreadditional vehicle systems to limit a speed at which the one or moreadditional vehicle systems move over the location of interest.
 13. Themethod of claim 1, wherein the vehicle system moves along the routeaccording to a reduced speed limit issued by an off-board protectionsystem, and further comprising: notifying the off-board protectionsystem that the change in the route has not occurred; and receiving amodification or elimination of the reduced speed limit from theoff-board protection system responsive to the off-board protectionsystem being notified that the change has not occurred.
 14. The methodof claim 1, further comprising: communicating a request to an off-boardsystem to one or more of inspect or repair the route at the location ofinterest responsive to determining that the change in the route hasoccurred.
 15. The method of claim 1, further comprising: restricting aspeed at which the vehicle system moves along the route responsive todetermining that the change in the route has occurred.
 16. The method ofclaim 1, wherein the change in the route includes one or more of a bendin a rail of a track, an indentation in the route, a rut in the route, apothole in the route, or an uncleaned area of the route.
 17. A systemcomprising: a controller configured to obtain first image data of aroute at a location of interest from a first optical sensor disposedonboard a vehicle system, the controller also configured to obtainsecond image data of the route at the location of interest from a secondoptical sensor disposed onboard the vehicle system, the second imagedata depicting the route at the location of interest after passage ofthe vehicle system over the route at the location of interest, andwherein the second image data is obtained responsive to a defined periodof time expiring following the first image data being obtained, thedefined period of time based on a distance between the first opticalsensor and the second optical sensor and a speed at which the vehiclesystem is moving.
 18. The system of claim 17, wherein the first imagedata depicts the route at the location of interest prior to passage ofthe vehicle system over the route at the location of interest.
 19. Thesystem of claim 17, wherein the controller configured to determinewhether a change in the route has occurred at the location of interestby comparing the first image data with the second image data.
 20. Asystem comprising: a controller configured to compare a first set ofimage data obtained ahead of a direction of movement of a vehicle systemwith a second set of the image data obtained behind the direction ofmovement of the vehicle system, wherein the second set of the image datais obtained responsive to a defined period of time expiring followingthe first set of the image data being obtained.